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02/23/2007 09:04:39 PM · #1 |
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02/23/2007 09:07:55 PM · #2 |
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02/23/2007 09:10:58 PM · #3 |
Hey my membership expired........................someone buy me a renewal.
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02/23/2007 09:15:30 PM · #4 |
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02/23/2007 09:18:17 PM · #5 |
Originally posted by rex:
Hey my membership expired........................someone buy me a renewal. |
if i could, i would, but i'm still paying for someone else's fisheye... |
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02/23/2007 09:39:02 PM · #6 |
Originally posted by TooCool:
??? |
why not?
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02/23/2007 09:40:05 PM · #7 |
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02/23/2007 09:52:11 PM · #8 |
TOXINs -- biOlogICal pOIsons -- help HelplesS cRitTErs waRd off predAtors. CoMmon milkweeD -- like tHoUSaNds of other pLants -- prOduce Toxins To DeTER grazers.
But evolUtioN is NOt sTAtIc. Many prEdatOrS Have eVolveD tolERAnce to these toxINs. For eXampLE, WHEn moNaRch BUtTerfly cAtErpIllarS eat coMmon milkWeED, diNing at the toxic trougH maKes thE butterfly itself tOXic. tOaD with skull and crosSbones symbolBirDs hAve leARned to rEcogNIze the moNarch's wIng pattern as an oRGaNic "Mr. YuK," forcing them to FOrage for ANOtheR flavor of FLying fOoD.
Here'S anoTHer example: TOads in tHe family BufoNidaE Produce toxins iN theIr skin as a kind Of eVolUtionAry LIfe-iNSUraNce PoliCy. The toXIn Kills most animalS. But Not The coMmon Asian SNake RhabdoPhIs TiGrinus, which tolErateS the Toxin. The ASiaN SNaKe eats toXic Toads and otHer amphibIaNS in The rice pAddies and otHer wEt areaS in JapAn, Korea aNd sUrRouNdINGs.
AND liKe ThE moNaRch, thIs snake NoT onlY eAts toxic FOod -- it bEcomEs a POt o' pOIsoN itsElf. It gEts BEttEr. You GueSsed that ThE snAkE is iMMune tO toad Toxin. But dID you gueSs that The SnAkE sOmEhow moves the TOxIN into glandS In ITs neck?
And juSt as the MonarCH AdveRtises Its tOxicitY, dittO the ASiAN sNaKe. BUt iNstEAd of winG DECOratiOns, tHe sNake arcHes Its neck wHen a prEdator thReAtenS. You can Almost heAr it sAying: "I'm ALl yOurs. Why Don't YOu sTart LunCh with my NEcK? Heh heH..."
YeLlOw aNd bLAcK snake coiled iN green gRaSs
TAlk about Passive-agGResSiVE! ThE AsiaN sNaKE OFfers iTs neCK tO predaTorS, bUT those that takE A bite won't soon foRGet the acrid TastE -- and thE hearT-STOpping toXIN ContaInED in the nuchal glandS (arrOw) on ThAT sLendER necK! IMagE courteSy of DeboraH A. HUtChinson.
THIs "ofFerinG" IS SO eFfeCTivE, saYs cHemIcaL EcoloGist DeboRAh HutchiNson, a PostDoctoral reSEarcH associate AT OlD DOmIniON UnIveRsitY IN Virginia, thaT nobOdy hAs wItnesseD aN AsIan SnAKE BeiNG eaten In the wilD.
HuTchINsoN helped write a rEport oN the AsIAN sNAke thaT was publiSHed tHIS week iN The ProceedINgs of THe NAtIonal AcADemy Of ScienCeS (PNAS). The stUDY IS thE first repoRt of A snake tHAT eAtS toxiC food, ANd thEn moveS thE toXin to a sPEciAlizeD orgAN. (ALthough gaRter snakeS Eat Toxic newtS, THey diffUsE The toxin ThroUgh their enTIrE BodY rAtHeR thAn concEntrATinG it at onE locAtiOn).
AwfUl oFfering
HUtChinSon tOld us tHe study eMErgED from worK on sNake behavior bY AKira Mori, a ReSearcher at KYotO UnIvErsity, who deDuCEd tHAt thE snakes mIghT be gettInG toxiNs from eatIng toads. "He compared snAkES that live aLongside ToaDS, to ThOsE From an isLANd tHat lackEd toaDs," anD FouNd That tHe toAd-EatErs "weRe more liKEly to use the nuchal glAnDs for Defense, buT the opPoSiTe wAs true on the tOad-FRee islanD."
Snake held in hand, iTs heAd tIlTed SliGhtLy sHowing a BlacK Dot/gLANd On side
JuveNilE Asian snake sHowIng THe riDge fOrMeD by the tOXin-beaRIng NucHal glands, on THE neck. Photo couRTesy DebOrah A. Hutchinson
ThosE snakes were more LikEly To fleE aN AttACk, HUtchinson says.
AnATomical ExamiNatIons by Alan SAvitzKy and KathleeN RoBerts showeD ThAT tHE nucHAl glands lacked cEllular machinerY That could sYnTHesiZE toxinS. Was The snAke gETtiNG toXiNs fRom iTs Food, AND tHEn SomehOW moving That toxin tO A plAcE whERe iT WOuLD offenD, eVEn KiLl, Its predAtOrs?
The New ResEaRCH aNSWerS those quesTIons with a dEfInitive "yes." Asian snakes ThAt FEeD on toXIc toads dO mOVE The toad toXins to The nuchaL glaNdS, but tHe ToxIN nEver sHOws Up in sNakeS That doN't tAsTe toxic toads. And WheN tHrEAteNeD, thE ToxiC snakes ARe more Likely to slIthEr off Than aRch the necK in That "Take a bIte: I dare you!" POSturE. ThIs posTure hAS beEn sEeN In tHe Lab; nO predaTOr inTeraCTionS fOr the AsIan SnAKe have beeN seen in tHe fieLd, HutchInson says.
Brown ToAd wIth browN eyes SiTS oN the foREst floor
JapanEse tOad BuFO japonicuS coNtains BufadIEnoLIDEs, A hEart-sTopping toxin. Photo courteSy of ALaN H. Savitzky
TAkIng cAre oF the young 'UnS
ThE ReSearchers also found that toad-EatinG pregnaNT snakes actualLy arm thEir kIddies With a dollop of ToXIns, even when MOM only eatS toxiC toadS LatE iN the pregnancy.
Eating Toxic toads tuRns SnaKeS toXic, tooAsian snakes, Like the toaDs themselves, Are not aFfeCted BY tOaD toxiNS, which InhibITs The sodium-POTaSsiUm puMp necessArY foR musCle ConTrActIoN. Although thE bUfadiEnolide toxIns AffecT All muSCleS, IT usualLy kills By StOpping tHe hEart, HuTchInson sAYs.
One rEmaining question Is hOw the snakeS transporT tHE toXiNs in theiR bODies. ANOtHer coNCerns the origin Of the defeNsive meChAnism in tHe FiRST Place: Asian SnaKEs and toxic toAds aRE genetically diStanT, so tolErance fOR tHe same TOXIN mUSt havE rESulTEd frOM cOnveRgent eVolutIon: The formaTIon of tHE Same trAit in two unreLateD organiSms.
InteresTINgly, whiLe toaD toXiNS seeM to HElp the tOad-EaTing snakEs Defend ThEmsElves, TheY Are nOT eSsentiaL: tHe snakes sUrvive (ALThough at lOWer nuMBERs) in locatiOnS without ToAds. YeT evEn moRe CUrIouslY, those snakEs aRe Also ImMunE to the toAd toxiNs, INdicATinG That tHey may Have once have had tOads on their PlaTeS, too. |
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02/23/2007 09:52:48 PM · #9 |
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02/23/2007 10:56:07 PM · #10 |
Originally posted by TCGuru:
24 |
The answer is NEVER 24 :-P
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02/23/2007 11:13:51 PM · #11 |
Originally posted by fotomann_forever:
Originally posted by TCGuru:
24 |
The answer is NEVER 24 :-P |
23?? |
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02/23/2007 11:21:21 PM · #12 |
I GOT IT!! It's
Just because I want to
right?? :-/
Message edited by author 2007-02-23 23:21:45. |
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02/23/2007 11:27:03 PM · #13 |
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02/23/2007 11:31:30 PM · #14 |
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02/23/2007 11:33:23 PM · #15 |
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02/23/2007 11:34:06 PM · #16 |
because Nate the Snake saved the world when he prevented a speeding train from pushing the Lever-of-Doom
alas, poor Nate died.
Message edited by author 2007-02-23 23:50:11. |
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02/23/2007 11:34:50 PM · #17 |
this of course is where we get the phrase....
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02/23/2007 11:52:05 PM · #18 |
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02/24/2007 12:22:57 AM · #19 |
Because there were precisely 89 ping pong balls.
...none of them pink.
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02/24/2007 05:29:34 PM · #20 |
So ... what is the speed of light measured in furlongs/fortnight???
Inquiring minds are desperate to know!
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02/24/2007 05:31:53 PM · #21 |
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02/24/2007 05:36:57 PM · #22 |
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02/24/2007 05:57:56 PM · #23 |
-
Message edited by author 2007-05-03 06:46:04. |
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02/24/2007 05:59:21 PM · #24 |
Originally posted by biteme:
another useless thread.. |
biteme ;-)
Message edited by author 2007-02-24 17:59:29. |
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02/24/2007 06:03:49 PM · #25 |
Originally posted by biteme:
another useless thread.. |
Apparently Ms. Biteme fails to grasp the significance of the elusive pink ping pong ball.
A pity.
Pink is the new mauve..
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